A material pack for the preparation of plate dentures comprises an outer pack formed of a material capable of shielding active energy beams. The outer pack contains a matrix formed of a light transmitting material, a photopolymerizable resin provided inside of the matrix, and artificial teeth provided on the matrix while a part thereof projects from the matrix into the photopolymerizable resin such that the artificial teeth are finely adjustable. The necessary particulars including, the size and form of the matrix, the size, form and color tone of the artificial teeth and the color tone of the photopolymerizable resin are specified on the outer pack.
1. Field of the Invention
The present invention relates to a material pack for the preparation of plate dentures, which makes it possible to prepare within a very short period of time a plate denture that is accommodative to the perculiarity of an individual, excels in fitting accuracy and aesthetics.
2. Statement of the Prior Art
Hitherto, plate dentures were prepared by making a wax denture based on a working model on which the oral mouth state of an individual was reproduced, and replacing the wax denture by a resin. Thus, since the process required for completing the plate denture was very lengthy, it took a period of as long as several weeks for an individual to obtain the completed plate denture. In the meantime, the individual had to live a toothless life.
General plate dentures relying upon a thermally polymerizable resin were prepared in the following manner. In order to reproduce the intra-mouth state of an individual on a working model, preliminary impression taking, preparation of a gypsum model, preparation of an individual tray, trying of the individual tray in the oral mouth, functional impression taking, preparation of the working model and correction of the form of the working model were first carried out. Then, preparation of a bite plate, bite taking, attachment of the bite plate to an articulator, arrangement of artificial teeth, trying and correction of a wax denture in the oral mouth and formation of gingival portion were carried out to make the wax denture. For subsequent replacement of the wax denture by the thermally polymerizable resin, investment of the wax denture, wax washing out, application of a resin separator, making the resin doughing, the resin filling, polymerization of the resin, and removal and polishing of the polymerized denture were conducted. Thus, a number of the steps were so many that it took a period of as long as several weeks for an individual to obtain the completed plate denture.
Many studies were made with a view to shortening the period of time needed for the preparation of plate dentures. In particular, there were proposed plate dentures designed for temporary use (hereinafter referred to as the temporary denture). In order to prepare the temporary dentures within a very short period of time, Japanese Patent Publication No. 46-24868, U.S. Pat. Nos. 3,460,252 and 3,621,575 disclose a combination of a temporary plate having a temporary arrangement of artificial teeth with a self-curing resin.
More specifically, the temporary plate having a temporary arrangement of artificial teeth provided in a matrix of the jaw form prepared using the average intra-mouth form as the model and formed of wax or polyethylene (hereinafter called the matrix) is used in combination with the self-curing resin. In order to prepare the temporary denture, the temporary plate having a temporary arrangement of artificial teeth is pressed against a gypsum model for adjustment. Afterwards, the self-curing resin is placed on the inside portion of the temporary plate forming the plate body, and the assembly is put over an objective, the impression of which is to be taken, followed by setting or curing by polymerization (hereinafter simply referred to as the polymerization or curing). The matrix portion is finally removed, and form adjustment is carried out to obtain the temporary denture.
The preparation of the temporary denture comprising a combination of the temporary plate having a temporary arrangement of artificial teeth with the self-curing resin is quite different from the aforesaid preparation of plate dentures relying upon the thermally polymerizable resin, and has an advantage thereover in that the finished temporary denture is available within a very short period of time, since the time needed for completing it is about 1 hour. However, any attention is hardly paid to fitting accuracy of the temporary denture with respect to the mucosal surface of the oral mouth, aesthetics of appearance such as the selection of artificial teeth and difficulty encountered in using the self-curing resin. Thus, the conventional temporary denture is still unsatisfactory due to its poor fitting accuracy with respect to the mucosal surface of the oral mouth and its cheap appearance.
Use of the self-curing resin also leads to various disadvantages in view of manipulations.
The disadvantages derived from the preparation of the temporary denture comprising a combination of the temporary plate having a temporary arrangement of artificial teeth with the self-curing resin are considered to be caused by the following reasons.
Since setting of the self-curing resin proceeds at room temperature, it sometimes occurs so prematurely that a time period allowed for manipulations such as muscle formation and centric relation biting is insufficient. It is difficult to carry out reliable fitting manipulation within a limited period of time of several minutes during which that resin is set.
In the course of this manipulation, setting of the self-curing resin placed inside of the temporary plate having a temporary arrangement of artificial teeth may come to an end. In this case, considerable time should be spent for removal of the set resin deposits, or a new temporary plate having a temporary arrangement of artificial teeth must be used.
Further, the polymerization of the self-curing resin generates the heat of reaction, which tends to deform the matrix portion of the temporary plate having a temporary arrangement of artificial teeth and formed of wax or polyethylene. In addition, since that heat of reaction causes the resin placed inside of the temporary plate to be set within a short time, air bubbles tend to occur on the application surface for impression taking or in narrow portions such as the portions of contact of the artificial teeth and the matrix portion with the resin. Such bubbles do not only cause the deposition of contaminants on the temporary denture during use, but also spoil the aesthetic appearance thereof. Still further, when the self-curing resin is directly pressed against the oral mouth in the doughing form, there is a fear that unpolymerized monomers may irritate the mucosa of the oral mouth. Still further, the artificial teeth used with the temporary plate having a temporary arrangement of artificial teeth is unsatisfactory in terms of their aesthetic appearance, since they cannot freely be selected according to individuality due to some limitations imposed upon the form, color tone and size thereof. Still further, since the artificial teeth are fixed in place in the matrix and, hence, cannot be adjusted finely with respect to the antagonists, their occlusal relation to the antagonists remains unsatisfactory.
As mentioned above, while the temporary denture comprising a combination of the temporary plate having a temporary arrangement of artificial teeth with the self-curing resin has the advantages that it can be prepared within a very short time, the obtained temporary denture has a number of disadvantages in terms of its fitting accuracy with respect to the mucosal surface of the oral mouth, aesthetics, or occlusal relation and manipulation properties. In other words, as good as the conventional temporary denture is in view of preparation alone, it is still considered to have its disadvantages.